Geriaviator
Maybe your Seletar Sunderlands were Mk V with Twin Wasp engines producing at least 20% more power, and did they carry armament?
Mark V's in 1958. ISTR they carried no armament, but could if necessary carry bombs and did so when engaged in FIREDOG missions over the Malayan jungle.
Meanwhile below two IWM photos of Mark III's photographed at Gan in WWII.
WT
